/*
        Winbond w9966cf Webcam parport driver.

        Version 0.32

        Copyright (C) 2001 Jakob Kemi <jakob.kemi@post.utfors.se>

        This program is free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
        the Free Software Foundation; either version 2 of the License, or
        (at your option) any later version.

        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.

        You should have received a copy of the GNU General Public License
        along with this program; if not, write to the Free Software
        Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
        Supported devices:
        *Lifeview FlyCam Supra (using the Philips saa7111a chip)

        Does any other model using the w9966 interface chip exist ?

        Todo:

        *Add a working EPP mode, since DMA ECP read isn't implemented
        in the parport drivers. (That's why it's so sloow)

        *Add support for other ccd-control chips than the saa7111
        please send me feedback on what kind of chips you have.

        *Add proper probing. I don't know what's wrong with the IEEE1284
        parport drivers but (IEEE1284_MODE_NIBBLE|IEEE1284_DEVICE_ID)
        and nibble read seems to be broken for some peripherals.

        *Add probing for onboard SRAM, port directions etc. (if possible)

        *Add support for the hardware compressed modes (maybe using v4l2)

        *Fix better support for the capture window (no skewed images, v4l
        interface to capt. window)

        *Probably some bugs that I don't know of

        Please support me by sending feedback!

        Changes:

        Alan Cox:       Removed RGB mode for kernel merge, added THIS_MODULE
                        and owner support for newer module locks
*/

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/videodev.h>
#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>
#include <linux/parport.h>

/*#define DEBUG*/                               /* Undef me for production */

#ifdef DEBUG
#define DPRINTF(x, a...) printk(KERN_DEBUG "W9966: %s(): "x, __func__ , ##a)
#else
#define DPRINTF(x...)
#endif

/*
 *      Defines, simple typedefs etc.
 */

#define W9966_DRIVERNAME        "W9966CF Webcam"
#define W9966_MAXCAMS           4       // Maximum number of cameras
#define W9966_RBUFFER           2048    // Read buffer (must be an even number)
#define W9966_SRAMSIZE          131072  // 128kb
#define W9966_SRAMID            0x02    // check w9966cf.pdf

// Empirically determined window limits
#define W9966_WND_MIN_X         16
#define W9966_WND_MIN_Y         14
#define W9966_WND_MAX_X         705
#define W9966_WND_MAX_Y         253
#define W9966_WND_MAX_W         (W9966_WND_MAX_X - W9966_WND_MIN_X)
#define W9966_WND_MAX_H         (W9966_WND_MAX_Y - W9966_WND_MIN_Y)

// Keep track of our current state
#define W9966_STATE_PDEV        0x01
#define W9966_STATE_CLAIMED     0x02
#define W9966_STATE_VDEV        0x04

#define W9966_I2C_W_ID          0x48
#define W9966_I2C_R_ID          0x49
#define W9966_I2C_R_DATA        0x08
#define W9966_I2C_R_CLOCK       0x04
#define W9966_I2C_W_DATA        0x02
#define W9966_I2C_W_CLOCK       0x01

struct w9966_dev {
        unsigned char dev_state;
        unsigned char i2c_state;
        unsigned short ppmode;
        struct parport* pport;
        struct pardevice* pdev;
        struct video_device vdev;
        unsigned short width;
        unsigned short height;
        unsigned char brightness;
        signed char contrast;
        signed char color;
        signed char hue;
        unsigned long in_use;
};

/*
 *      Module specific properties
 */

MODULE_AUTHOR("Jakob Kemi <jakob.kemi@post.utfors.se>");
MODULE_DESCRIPTION("Winbond w9966cf WebCam driver (0.32)");
MODULE_LICENSE("GPL");


#ifdef MODULE
static const char* pardev[] = {[0 ... W9966_MAXCAMS] = ""};
#else
static const char* pardev[] = {[0 ... W9966_MAXCAMS] = "aggressive"};
#endif
module_param_array(pardev, charp, NULL, 0);
MODULE_PARM_DESC(pardev, "pardev: where to search for\n\
\teach camera. 'aggressive' means brute-force search.\n\
\tEg: >pardev=parport3,aggressive,parport2,parport1< would assign\n\
\tcam 1 to parport3 and search every parport for cam 2 etc...");

static int parmode;
module_param(parmode, int, 0);
MODULE_PARM_DESC(parmode, "parmode: transfer mode (0=auto, 1=ecp, 2=epp");

static int video_nr = -1;
module_param(video_nr, int, 0);

/*
 *      Private data
 */

static struct w9966_dev w9966_cams[W9966_MAXCAMS];

/*
 *      Private function declares
 */

static inline void w9966_setState(struct w9966_dev* cam, int mask, int val);
static inline int  w9966_getState(struct w9966_dev* cam, int mask, int val);
static inline void w9966_pdev_claim(struct w9966_dev *vdev);
static inline void w9966_pdev_release(struct w9966_dev *vdev);

static int w9966_rReg(struct w9966_dev* cam, int reg);
static int w9966_wReg(struct w9966_dev* cam, int reg, int data);
#if 0
static int w9966_rReg_i2c(struct w9966_dev* cam, int reg);
#endif
static int w9966_wReg_i2c(struct w9966_dev* cam, int reg, int data);
static int w9966_findlen(int near, int size, int maxlen);
static int w9966_calcscale(int size, int min, int max, int* beg, int* end, unsigned char* factor);
static int w9966_setup(struct w9966_dev* cam, int x1, int y1, int x2, int y2, int w, int h);

static int  w9966_init(struct w9966_dev* cam, struct parport* port);
static void w9966_term(struct w9966_dev* cam);

static inline void w9966_i2c_setsda(struct w9966_dev* cam, int state);
static inline int  w9966_i2c_setscl(struct w9966_dev* cam, int state);
static inline int  w9966_i2c_getsda(struct w9966_dev* cam);
static inline int  w9966_i2c_getscl(struct w9966_dev* cam);
static int w9966_i2c_wbyte(struct w9966_dev* cam, int data);
#if 0
static int w9966_i2c_rbyte(struct w9966_dev* cam);
#endif

static long w9966_v4l_ioctl(struct file *file,
                           unsigned int cmd, unsigned long arg);
static ssize_t w9966_v4l_read(struct file *file, char __user *buf,
                              size_t count, loff_t *ppos);

static int w9966_exclusive_open(struct file *file)
{
        struct w9966_dev *cam = video_drvdata(file);

        return test_and_set_bit(0, &cam->in_use) ? -EBUSY : 0;
}

static int w9966_exclusive_release(struct file *file)
{
        struct w9966_dev *cam = video_drvdata(file);

        clear_bit(0, &cam->in_use);
        return 0;
}

static const struct v4l2_file_operations w9966_fops = {
        .owner          = THIS_MODULE,
        .open           = w9966_exclusive_open,
        .release        = w9966_exclusive_release,
        .ioctl          = w9966_v4l_ioctl,
        .read           = w9966_v4l_read,
};
static struct video_device w9966_template = {
        .name           = W9966_DRIVERNAME,
        .fops           = &w9966_fops,
        .release        = video_device_release_empty,
};

/*
 *      Private function defines
 */


// Set camera phase flags, so we know what to uninit when terminating
static inline void w9966_setState(struct w9966_dev* cam, int mask, int val)
{
        cam->dev_state = (cam->dev_state & ~mask) ^ val;
}

// Get camera phase flags
static inline int w9966_getState(struct w9966_dev* cam, int mask, int val)
{
        return ((cam->dev_state & mask) == val);
}

// Claim parport for ourself
static inline void w9966_pdev_claim(struct w9966_dev* cam)
{
        if (w9966_getState(cam, W9966_STATE_CLAIMED, W9966_STATE_CLAIMED))
                return;
        parport_claim_or_block(cam->pdev);
        w9966_setState(cam, W9966_STATE_CLAIMED, W9966_STATE_CLAIMED);
}

// Release parport for others to use
static inline void w9966_pdev_release(struct w9966_dev* cam)
{
        if (w9966_getState(cam, W9966_STATE_CLAIMED, 0))
                return;
        parport_release(cam->pdev);
        w9966_setState(cam, W9966_STATE_CLAIMED, 0);
}

// Read register from W9966 interface-chip
// Expects a claimed pdev
// -1 on error, else register data (byte)
static int w9966_rReg(struct w9966_dev* cam, int reg)
{
        // ECP, read, regtransfer, REG, REG, REG, REG, REG
        const unsigned char addr = 0x80 | (reg & 0x1f);
        unsigned char val;

        if (parport_negotiate(cam->pport, cam->ppmode | IEEE1284_ADDR) != 0)
                return -1;
        if (parport_write(cam->pport, &addr, 1) != 1)
                return -1;
        if (parport_negotiate(cam->pport, cam->ppmode | IEEE1284_DATA) != 0)
                return -1;
        if (parport_read(cam->pport, &val, 1) != 1)
                return -1;

        return val;
}

// Write register to W9966 interface-chip
// Expects a claimed pdev
// -1 on error
static int w9966_wReg(struct w9966_dev* cam, int reg, int data)
{
        // ECP, write, regtransfer, REG, REG, REG, REG, REG
        const unsigned char addr = 0xc0 | (reg & 0x1f);
        const unsigned char val = data;

        if (parport_negotiate(cam->pport, cam->ppmode | IEEE1284_ADDR) != 0)
                return -1;
        if (parport_write(cam->pport, &addr, 1) != 1)
                return -1;
        if (parport_negotiate(cam->pport, cam->ppmode | IEEE1284_DATA) != 0)
                return -1;
        if (parport_write(cam->pport, &val, 1) != 1)
                return -1;

        return 0;
}

// Initialize camera device. Setup all internal flags, set a
// default video mode, setup ccd-chip, register v4l device etc..
// Also used for 'probing' of hardware.
// -1 on error
static int w9966_init(struct w9966_dev* cam, struct parport* port)
{
        if (cam->dev_state != 0)
                return -1;

        cam->pport = port;
        cam->brightness = 128;
        cam->contrast = 64;
        cam->color = 64;
        cam->hue = 0;

// Select requested transfer mode
        switch(parmode)
        {
        default:        // Auto-detect (priority: hw-ecp, hw-epp, sw-ecp)
        case 0:
                if (port->modes & PARPORT_MODE_ECP)
                        cam->ppmode = IEEE1284_MODE_ECP;
                else if (port->modes & PARPORT_MODE_EPP)
                        cam->ppmode = IEEE1284_MODE_EPP;
                else
                        cam->ppmode = IEEE1284_MODE_ECP;
                break;
        case 1:         // hw- or sw-ecp
                cam->ppmode = IEEE1284_MODE_ECP;
                break;
        case 2:         // hw- or sw-epp
                cam->ppmode = IEEE1284_MODE_EPP;
        break;
        }

// Tell the parport driver that we exists
        cam->pdev = parport_register_device(port, "w9966", NULL, NULL, NULL, 0, NULL);
        if (cam->pdev == NULL) {
                DPRINTF("parport_register_device() failed\n");
                return -1;
        }
        w9966_setState(cam, W9966_STATE_PDEV, W9966_STATE_PDEV);

        w9966_pdev_claim(cam);

// Setup a default capture mode
        if (w9966_setup(cam, 0, 0, 1023, 1023, 200, 160) != 0) {
                DPRINTF("w9966_setup() failed.\n");
                return -1;
        }

        w9966_pdev_release(cam);

// Fill in the video_device struct and register us to v4l
        memcpy(&cam->vdev, &w9966_template, sizeof(struct video_device));
        video_set_drvdata(&cam->vdev, cam);

        if (video_register_device(&cam->vdev, VFL_TYPE_GRABBER, video_nr) < 0)
                return -1;

        w9966_setState(cam, W9966_STATE_VDEV, W9966_STATE_VDEV);

        // All ok
        printk(
                "w9966cf: Found and initialized a webcam on %s.\n",
                cam->pport->name
        );
        return 0;
}


// Terminate everything gracefully
static void w9966_term(struct w9966_dev* cam)
{
// Unregister from v4l
        if (w9966_getState(cam, W9966_STATE_VDEV, W9966_STATE_VDEV)) {
                video_unregister_device(&cam->vdev);
                w9966_setState(cam, W9966_STATE_VDEV, 0);
        }

// Terminate from IEEE1284 mode and release pdev block
        if (w9966_getState(cam, W9966_STATE_PDEV, W9966_STATE_PDEV)) {
                w9966_pdev_claim(cam);
                parport_negotiate(cam->pport, IEEE1284_MODE_COMPAT);
                w9966_pdev_release(cam);
        }

// Unregister from parport
        if (w9966_getState(cam, W9966_STATE_PDEV, W9966_STATE_PDEV)) {
                parport_unregister_device(cam->pdev);
                w9966_setState(cam, W9966_STATE_PDEV, 0);
        }
}


// Find a good length for capture window (used both for W and H)
// A bit ugly but pretty functional. The capture length
// have to match the downscale
static int w9966_findlen(int near, int size, int maxlen)
{
        int bestlen = size;
        int besterr = abs(near - bestlen);
        int len;

        for(len = size+1;len < maxlen;len++)
        {
                int err;
                if ( ((64*size) %len) != 0)
                        continue;

                err = abs(near - len);

                // Only continue as long as we keep getting better values
                if (err > besterr)
                        break;

                besterr = err;
                bestlen = len;
        }

        return bestlen;
}

// Modify capture window (if necessary)
// and calculate downscaling
// Return -1 on error
static int w9966_calcscale(int size, int min, int max, int* beg, int* end, unsigned char* factor)
{
        int maxlen = max - min;
        int len = *end - *beg + 1;
        int newlen = w9966_findlen(len, size, maxlen);
        int err = newlen - len;

        // Check for bad format
        if (newlen > maxlen || newlen < size)
                return -1;

        // Set factor (6 bit fixed)
        *factor = (64*size) / newlen;
        if (*factor == 64)
                *factor = 0x00; // downscale is disabled
        else
                *factor |= 0x80; // set downscale-enable bit

        // Modify old beginning and end
        *beg -= err / 2;
        *end += err - (err / 2);

        // Move window if outside borders
        if (*beg < min) {
                *end += min - *beg;
                *beg += min - *beg;
        }
        if (*end > max) {
                *beg -= *end - max;
                *end -= *end - max;
        }

        return 0;
}

// Setup the cameras capture window etc.
// Expects a claimed pdev
// return -1 on error
static int w9966_setup(struct w9966_dev* cam, int x1, int y1, int x2, int y2, int w, int h)
{
        unsigned int i;
        unsigned int enh_s, enh_e;
        unsigned char scale_x, scale_y;
        unsigned char regs[0x1c];
        unsigned char saa7111_regs[] = {
                0x21, 0x00, 0xd8, 0x23, 0x00, 0x80, 0x80, 0x00,
                0x88, 0x10, 0x80, 0x40, 0x40, 0x00, 0x01, 0x00,
                0x48, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x71, 0xe7, 0x00, 0x00, 0xc0
        };


        if (w*h*2 > W9966_SRAMSIZE)
        {
                DPRINTF("capture window exceeds SRAM size!.\n");
                w = 200; h = 160;       // Pick default values
        }

        w &= ~0x1;
        if (w < 2) w = 2;
        if (h < 1) h = 1;
        if (w > W9966_WND_MAX_W) w = W9966_WND_MAX_W;
        if (h > W9966_WND_MAX_H) h = W9966_WND_MAX_H;

        cam->width = w;
        cam->height = h;

        enh_s = 0;
        enh_e = w*h*2;

// Modify capture window if necessary and calculate downscaling
        if (
                w9966_calcscale(w, W9966_WND_MIN_X, W9966_WND_MAX_X, &x1, &x2, &scale_x) != 0 ||
                w9966_calcscale(h, W9966_WND_MIN_Y, W9966_WND_MAX_Y, &y1, &y2, &scale_y) != 0
        ) return -1;

        DPRINTF(
                "%dx%d, x: %d<->%d, y: %d<->%d, sx: %d/64, sy: %d/64.\n",
                w, h, x1, x2, y1, y2, scale_x&~0x80, scale_y&~0x80
        );

// Setup registers
        regs[0x00] = 0x00;                      // Set normal operation
        regs[0x01] = 0x18;                      // Capture mode
        regs[0x02] = scale_y;                   // V-scaling
        regs[0x03] = scale_x;                   // H-scaling

        // Capture window
        regs[0x04] = (x1 & 0x0ff);              // X-start (8 low bits)
        regs[0x05] = (x1 & 0x300)>>8;           // X-start (2 high bits)
        regs[0x06] = (y1 & 0x0ff);              // Y-start (8 low bits)
        regs[0x07] = (y1 & 0x300)>>8;           // Y-start (2 high bits)
        regs[0x08] = (x2 & 0x0ff);              // X-end (8 low bits)
        regs[0x09] = (x2 & 0x300)>>8;           // X-end (2 high bits)
        regs[0x0a] = (y2 & 0x0ff);              // Y-end (8 low bits)

        regs[0x0c] = W9966_SRAMID;              // SRAM-banks (1x 128kb)

        // Enhancement layer
        regs[0x0d] = (enh_s& 0x000ff);          // Enh. start (0-7)
        regs[0x0e] = (enh_s& 0x0ff00)>>8;       // Enh. start (8-15)
        regs[0x0f] = (enh_s& 0x70000)>>16;      // Enh. start (16-17/18??)
        regs[0x10] = (enh_e& 0x000ff);          // Enh. end (0-7)
        regs[0x11] = (enh_e& 0x0ff00)>>8;       // Enh. end (8-15)
        regs[0x12] = (enh_e& 0x70000)>>16;      // Enh. end (16-17/18??)

        // Misc
        regs[0x13] = 0x40;                      // VEE control (raw 4:2:2)
        regs[0x17] = 0x00;                      // ???
        regs[0x18] = cam->i2c_state = 0x00;     // Serial bus
        regs[0x19] = 0xff;                      // I/O port direction control
        regs[0x1a] = 0xff;                      // I/O port data register
        regs[0x1b] = 0x10;                      // ???

        // SAA7111 chip settings
        saa7111_regs[0x0a] = cam->brightness;
        saa7111_regs[0x0b] = cam->contrast;
        saa7111_regs[0x0c] = cam->color;
        saa7111_regs[0x0d] = cam->hue;

// Reset (ECP-fifo & serial-bus)
        if (w9966_wReg(cam, 0x00, 0x03) == -1)
                return -1;

// Write regs to w9966cf chip
        for (i = 0; i < 0x1c; i++)
                if (w9966_wReg(cam, i, regs[i]) == -1)
                        return -1;

// Write regs to saa7111 chip
        for (i = 0; i < 0x20; i++)
                if (w9966_wReg_i2c(cam, i, saa7111_regs[i]) == -1)
                        return -1;

        return 0;
}

/*
 *      Ugly and primitive i2c protocol functions
 */

// Sets the data line on the i2c bus.
// Expects a claimed pdev.
static inline void w9966_i2c_setsda(struct w9966_dev* cam, int state)
{
        if (state)
                cam->i2c_state |= W9966_I2C_W_DATA;
        else
                cam->i2c_state &= ~W9966_I2C_W_DATA;

        w9966_wReg(cam, 0x18, cam->i2c_state);
        udelay(5);
}

// Get peripheral clock line
// Expects a claimed pdev.
static inline int w9966_i2c_getscl(struct w9966_dev* cam)
{
        const unsigned char state = w9966_rReg(cam, 0x18);
        return ((state & W9966_I2C_R_CLOCK) > 0);
}

// Sets the clock line on the i2c bus.
// Expects a claimed pdev. -1 on error
static inline int w9966_i2c_setscl(struct w9966_dev* cam, int state)
{
        unsigned long timeout;

        if (state)
                cam->i2c_state |= W9966_I2C_W_CLOCK;
        else
                cam->i2c_state &= ~W9966_I2C_W_CLOCK;

        w9966_wReg(cam, 0x18, cam->i2c_state);
        udelay(5);

        // we go to high, we also expect the peripheral to ack.
        if (state) {
                timeout = jiffies + 100;
                while (!w9966_i2c_getscl(cam)) {
                        if (time_after(jiffies, timeout))
                                return -1;
                }
        }
        return 0;
}

// Get peripheral data line
// Expects a claimed pdev.
static inline int w9966_i2c_getsda(struct w9966_dev* cam)
{
        const unsigned char state = w9966_rReg(cam, 0x18);
        return ((state & W9966_I2C_R_DATA) > 0);
}

// Write a byte with ack to the i2c bus.
// Expects a claimed pdev. -1 on error
static int w9966_i2c_wbyte(struct w9966_dev* cam, int data)
{
        int i;
        for (i = 7; i >= 0; i--)
        {
                w9966_i2c_setsda(cam, (data >> i) & 0x01);

                if (w9966_i2c_setscl(cam, 1) == -1)
                        return -1;
                w9966_i2c_setscl(cam, 0);
        }

        w9966_i2c_setsda(cam, 1);

        if (w9966_i2c_setscl(cam, 1) == -1)
                return -1;
        w9966_i2c_setscl(cam, 0);

        return 0;
}

// Read a data byte with ack from the i2c-bus
// Expects a claimed pdev. -1 on error
#if 0
static int w9966_i2c_rbyte(struct w9966_dev* cam)
{
        unsigned char data = 0x00;
        int i;

        w9966_i2c_setsda(cam, 1);

        for (i = 0; i < 8; i++)
        {
                if (w9966_i2c_setscl(cam, 1) == -1)
                        return -1;
                data = data << 1;
                if (w9966_i2c_getsda(cam))
                        data |= 0x01;

                w9966_i2c_setscl(cam, 0);
        }
        return data;
}
#endif

// Read a register from the i2c device.
// Expects claimed pdev. -1 on error
#if 0
static int w9966_rReg_i2c(struct w9966_dev* cam, int reg)
{
        int data;

        w9966_i2c_setsda(cam, 0);
        w9966_i2c_setscl(cam, 0);

        if (
                w9966_i2c_wbyte(cam, W9966_I2C_W_ID) == -1 ||
                w9966_i2c_wbyte(cam, reg) == -1
        )
                return -1;

        w9966_i2c_setsda(cam, 1);
        if (w9966_i2c_setscl(cam, 1) == -1)
                return -1;
        w9966_i2c_setsda(cam, 0);
        w9966_i2c_setscl(cam, 0);

        if (
                w9966_i2c_wbyte(cam, W9966_I2C_R_ID) == -1 ||
                (data = w9966_i2c_rbyte(cam)) == -1
        )
                return -1;

        w9966_i2c_setsda(cam, 0);

        if (w9966_i2c_setscl(cam, 1) == -1)
                return -1;
        w9966_i2c_setsda(cam, 1);

        return data;
}
#endif

// Write a register to the i2c device.
// Expects claimed pdev. -1 on error
static int w9966_wReg_i2c(struct w9966_dev* cam, int reg, int data)
{
        w9966_i2c_setsda(cam, 0);
        w9966_i2c_setscl(cam, 0);

        if (
                w9966_i2c_wbyte(cam, W9966_I2C_W_ID) == -1 ||
                w9966_i2c_wbyte(cam, reg) == -1 ||
                w9966_i2c_wbyte(cam, data) == -1
        )
                return -1;

        w9966_i2c_setsda(cam, 0);
        if (w9966_i2c_setscl(cam, 1) == -1)
                return -1;

        w9966_i2c_setsda(cam, 1);

        return 0;
}

/*
 *      Video4linux interfacing
 */

static long w9966_v4l_do_ioctl(struct file *file, unsigned int cmd, void *arg)
{
        struct w9966_dev *cam = video_drvdata(file);

        switch(cmd)
        {
        case VIDIOCGCAP:
        {
                static struct video_capability vcap = {
                        .name      = W9966_DRIVERNAME,
                        .type      = VID_TYPE_CAPTURE | VID_TYPE_SCALES,
                        .channels  = 1,
                        .maxwidth  = W9966_WND_MAX_W,
                        .maxheight = W9966_WND_MAX_H,
                        .minwidth  = 2,
                        .minheight = 1,
                };
                struct video_capability *cap = arg;
                *cap = vcap;
                return 0;
        }
        case VIDIOCGCHAN:
        {
                struct video_channel *vch = arg;
                if(vch->channel != 0)   // We only support one channel (#0)
                        return -EINVAL;
                memset(vch,0,sizeof(*vch));
                strcpy(vch->name, "CCD-input");
                vch->type = VIDEO_TYPE_CAMERA;
                return 0;
        }
        case VIDIOCSCHAN:
        {
                struct video_channel *vch = arg;
                if(vch->channel != 0)
                        return -EINVAL;
                return 0;
        }
        case VIDIOCGTUNER:
        {
                struct video_tuner *vtune = arg;
                if(vtune->tuner != 0)
                        return -EINVAL;
                strcpy(vtune->name, "no tuner");
                vtune->rangelow = 0;
                vtune->rangehigh = 0;
                vtune->flags = VIDEO_TUNER_NORM;
                vtune->mode = VIDEO_MODE_AUTO;
                vtune->signal = 0xffff;
                return 0;
        }
        case VIDIOCSTUNER:
        {
                struct video_tuner *vtune = arg;
                if (vtune->tuner != 0)
                        return -EINVAL;
                if (vtune->mode != VIDEO_MODE_AUTO)
                        return -EINVAL;
                return 0;
        }
        case VIDIOCGPICT:
        {
                struct video_picture vpic = {
                        cam->brightness << 8,   // brightness
                        (cam->hue + 128) << 8,  // hue
                        cam->color << 9,        // color
                        cam->contrast << 9,     // contrast
                        0x8000,                 // whiteness
                        16, VIDEO_PALETTE_YUV422// bpp, palette format
                };
                struct video_picture *pic = arg;
                *pic = vpic;
                return 0;
        }
        case VIDIOCSPICT:
        {
                struct video_picture *vpic = arg;
                if (vpic->depth != 16 || (vpic->palette != VIDEO_PALETTE_YUV422 && vpic->palette != VIDEO_PALETTE_YUYV))
                        return -EINVAL;

                cam->brightness = vpic->brightness >> 8;
                cam->hue = (vpic->hue >> 8) - 128;
                cam->color = vpic->colour >> 9;
                cam->contrast = vpic->contrast >> 9;

                w9966_pdev_claim(cam);

                if (
                        w9966_wReg_i2c(cam, 0x0a, cam->brightness) == -1 ||
                        w9966_wReg_i2c(cam, 0x0b, cam->contrast) == -1 ||
                        w9966_wReg_i2c(cam, 0x0c, cam->color) == -1 ||
                        w9966_wReg_i2c(cam, 0x0d, cam->hue) == -1
                ) {
                        w9966_pdev_release(cam);
                        return -EIO;
                }

                w9966_pdev_release(cam);
                return 0;
        }
        case VIDIOCSWIN:
        {
                int ret;
                struct video_window *vwin = arg;

                if (vwin->flags != 0)
                        return -EINVAL;
                if (vwin->clipcount != 0)
                        return -EINVAL;
                if (vwin->width < 2 || vwin->width > W9966_WND_MAX_W)
                        return -EINVAL;
                if (vwin->height < 1 || vwin->height > W9966_WND_MAX_H)
                        return -EINVAL;

                // Update camera regs
                w9966_pdev_claim(cam);
                ret = w9966_setup(cam, 0, 0, 1023, 1023, vwin->width, vwin->height);
                w9966_pdev_release(cam);

                if (ret != 0) {
                        DPRINTF("VIDIOCSWIN: w9966_setup() failed.\n");
                        return -EIO;
                }

                return 0;
        }
        case VIDIOCGWIN:
        {
                struct video_window *vwin = arg;
                memset(vwin, 0, sizeof(*vwin));
                vwin->width = cam->width;
                vwin->height = cam->height;
                return 0;
        }
        // Unimplemented
        case VIDIOCCAPTURE:
        case VIDIOCGFBUF:
        case VIDIOCSFBUF:
        case VIDIOCKEY:
        case VIDIOCGFREQ:
        case VIDIOCSFREQ:
        case VIDIOCGAUDIO:
        case VIDIOCSAUDIO:
                return -EINVAL;
        default:
                return -ENOIOCTLCMD;
        }
        return 0;
}

static long w9966_v4l_ioctl(struct file *file,
                           unsigned int cmd, unsigned long arg)
{
        return video_usercopy(file, cmd, arg, w9966_v4l_do_ioctl);
}

// Capture data
static ssize_t w9966_v4l_read(struct file *file, char  __user *buf,
                              size_t count, loff_t *ppos)
{
        struct w9966_dev *cam = video_drvdata(file);
        unsigned char addr = 0xa0;      // ECP, read, CCD-transfer, 00000
        unsigned char __user *dest = (unsigned char __user *)buf;
        unsigned long dleft = count;
        unsigned char *tbuf;

        // Why would anyone want more than this??
        if (count > cam->width * cam->height * 2)
                return -EINVAL;

        w9966_pdev_claim(cam);
        w9966_wReg(cam, 0x00, 0x02);    // Reset ECP-FIFO buffer
        w9966_wReg(cam, 0x00, 0x00);    // Return to normal operation
        w9966_wReg(cam, 0x01, 0x98);    // Enable capture

        // write special capture-addr and negotiate into data transfer
        if (
                (parport_negotiate(cam->pport, cam->ppmode|IEEE1284_ADDR) != 0  )||
                (parport_write(cam->pport, &addr, 1) != 1                                               )||
                (parport_negotiate(cam->pport, cam->ppmode|IEEE1284_DATA) != 0  )
        ) {
                w9966_pdev_release(cam);
                return -EFAULT;
        }

        tbuf = kmalloc(W9966_RBUFFER, GFP_KERNEL);
        if (tbuf == NULL) {
                count = -ENOMEM;
                goto out;
        }

        while(dleft > 0)
        {
                unsigned long tsize = (dleft > W9966_RBUFFER) ? W9966_RBUFFER : dleft;

                if (parport_read(cam->pport, tbuf, tsize) < tsize) {
                        count = -EFAULT;
                        goto out;
                }
                if (copy_to_user(dest, tbuf, tsize) != 0) {
                        count = -EFAULT;
                        goto out;
                }
                dest += tsize;
                dleft -= tsize;
        }

        w9966_wReg(cam, 0x01, 0x18);    // Disable capture

out:
        kfree(tbuf);
        w9966_pdev_release(cam);

        return count;
}


// Called once for every parport on init
static void w9966_attach(struct parport *port)
{
        int i;

        for (i = 0; i < W9966_MAXCAMS; i++)
        {
                if (w9966_cams[i].dev_state != 0)       // Cam is already assigned
                        continue;
                if (
                        strcmp(pardev[i], "aggressive") == 0 ||
                        strcmp(pardev[i], port->name) == 0
                ) {
                        if (w9966_init(&w9966_cams[i], port) != 0)
                        w9966_term(&w9966_cams[i]);
                        break;  // return
                }
        }
}

// Called once for every parport on termination
static void w9966_detach(struct parport *port)
{
        int i;
        for (i = 0; i < W9966_MAXCAMS; i++)
        if (w9966_cams[i].dev_state != 0 && w9966_cams[i].pport == port)
                w9966_term(&w9966_cams[i]);
}


static struct parport_driver w9966_ppd = {
        .name = W9966_DRIVERNAME,
        .attach = w9966_attach,
        .detach = w9966_detach,
};

// Module entry point
static int __init w9966_mod_init(void)
{
        int i;
        for (i = 0; i < W9966_MAXCAMS; i++)
                w9966_cams[i].dev_state = 0;

        return parport_register_driver(&w9966_ppd);
}

// Module cleanup
static void __exit w9966_mod_term(void)
{
        parport_unregister_driver(&w9966_ppd);
}

module_init(w9966_mod_init);
module_exit(w9966_mod_term);